Each newsletter costs 38 cents to produce
475,000 newsletters are produced in a week
475,000 * 0.38 = $180,500 (the cost to produce and mail the newsletter each week)
If we assume that 1 month = 4 weeks, then the cost to produce and mail the newsletter each month is
4 * 180,500 = $722,000
If you want to be a bit more precise, you can state that 1 month is approximately 4.3 weeks because:
There are 52 weeks in one year, and 12 months in one year, so there are
52/12 = 13/3 = 4.3333........ weeks in one month